Environmental Assessment of Laundry Detergents
- surface active substances have cleaning/degreasing capabilities
- reduces surface tension
- hydrophobic and hydrophilic portions
- hydrophobic carbon based portion is neutral
- hydrophilic portion determines classification: non-ionic, anionic, cationic
- anionic: negatively charged hydrophilic portion (ex. sulfonate)
- sensitive to water hardness
- nonionic: neutral charged hydrophilic portion (ex. ethoxylate)
- good for use in detergents; can use even with hard water
- cationic: positive charged hydrophilic portion (ex. quaternary ammonium)
- can be used on surfaces to prevent soil from sticking
- amphoteric: charge of hydrophilic portion depends on pH of medium
- can act as anionic or cationic
- linear chains more easily biodegraded than branched
- general increase in toxicity when hydrocarbon chain has more carbons
- anionic linear alkyl benzene sulfonates: major component of laundry/cleaning detergents
- don't biodegrade readily in anearobic conditions
- alkyl phenol ethoxylates: toxicity to environment caused its use to dwindle in detergent industry